1. Field of the Invention
This invention pertains to fan blade filters and more particularly, to fan blade filters that are secured to the leading edge of rotating fan blades.
2. General Background
As the use of ceiling fans grow in popularity, there becomes a greater need to filter the circulating air. In the past, when filtered air was circulated it my have been through the use of a central building unit or possibly a window air-conditioning unit, both of which filter the air entering the room. Ceiling fans, however, are not so easily adaptable to these types of filters, as it is unreasonable to build a cage around the rotating blades so as to filter the moving air.
U.S Pat. No. 3,126,263 issued to L. Schwab entitled "Gas Deflecting And Filtering" discloses a fan having filter material 46 which is rotated and through which air passes. As shown in FIG. 2, thereof, the filter material not only covers the rotating vanes, but also the space between them thereby presenting the appearance of a rotating disc. It would be impractical to cover the multiple blades of a ceiling fan with one large circular disc as described herein because to do so would destroy the circulating effect of the individual blades that makes ceiling fans desirable in the first place.
U.S. Pat. No. 3,347,025 issued to M. Wiley entitled "Air Circulation System" and U.S. Pat. No. 3,577,710 issued to E. I Feldman entitled "Air-Treatment Apparatus" both disclose fans having their air passages covered by stationary filter elements. Again, for the reasons cited above, to place a stationary filter material either above or below the rotating blades would not only be cumbersome, but would also significantly reduce the circulating effect which is so highly prized.
U.S. Pat. No. 4,422,824 issued to C. A. Eisenhardt, Jr. entitled "Germicidal Ceiling Fan Blade" discloses a ceiling fan blade having a hollow chamber into which a germicidal light is placed. Filtering pads 28 thereof are installed along the leading and trailing edges of each blade enabling air and air-borne micro-organisms to pass into the chamber. Once in the chamber, the germicidal light destroys any micro-organisms contained in the passing air. When one considers the fact that in a ceiling fan the weight of the rotating vanes is of utmost importance (they must be delicately cross balanced to avoid any irregular rotation), the weight of each vane, and the likelihood of unevenly weighted vanes, makes this invention impractical for all but the stoutest of motors and sturdiest of mounts.
U.S. Pat. No. 4,596,585 issued to D. W. Moeller, et al. entitled "Method And Apparatus For Reduction Of Radon Decay Product Exposure" discloses an ion-generator suspended just below the rotating blades to create special distribution of air-borne charged ions. These ions are used to reduce the amount of the radon decay products suspended in the air.
U.S. Pat. No. 4,676,721 issued to S. D. Hardee entitled "Room Air Cleaner" and EP 196-337-A both disclose a fan whose blade surface is covered by a filter material. As the covered vanes rotate, the filter material traps air-borne particles. The operation of this patented technology is clearly understandable. The foam blocks of the European patent need to be accurately cut so as to maintain the critical balance of the rotating blades while the vane sock of Hardee '721 must be tailored to accommodate a variety of differently configured vanes.
It is thus an object of this invention to provide a practical ceiling fan filter that does not have the shortcomings mentioned hereinabove. It is a futher object of this invention to provide a ceiling fan filter that is lightweight, compact, unobtrusive, and functional.